agp: Switch agp_{un,}map_page() to take struct page * argument

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
index 3c3a487..343f102 100644
--- a/drivers/char/agp/backend.c
+++ b/drivers/char/agp/backend.c
@@ -149,9 +149,9 @@
 			return -ENOMEM;
 		}
 
-		bridge->scratch_page_real = phys_to_gart(page_to_phys(page));
+		bridge->scratch_page_page = page;
 		if (bridge->driver->agp_map_page) {
-			if (bridge->driver->agp_map_page(phys_to_virt(page_to_phys(page)),
+			if (bridge->driver->agp_map_page(page,
 							 &bridge->scratch_page_dma)) {
 				dev_err(&bridge->dev->dev,
 					"unable to dma-map scratch page\n");
@@ -205,13 +205,12 @@
 err_out:
 	if (bridge->driver->needs_scratch_page &&
 	    bridge->driver->agp_unmap_page) {
-		void *va = gart_to_virt(bridge->scratch_page_real);
-
-		bridge->driver->agp_unmap_page(va, bridge->scratch_page_dma);
+		bridge->driver->agp_unmap_page(bridge->scratch_page_page,
+					       bridge->scratch_page_dma);
 	}
 err_out_nounmap:
 	if (bridge->driver->needs_scratch_page) {
-		void *va = gart_to_virt(bridge->scratch_page_real);
+		void *va = page_address(bridge->scratch_page_page);
 
 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
@@ -238,11 +237,11 @@
 
 	if (bridge->driver->agp_destroy_page &&
 	    bridge->driver->needs_scratch_page) {
-		void *va = gart_to_virt(bridge->scratch_page_real);
+		void *va = page_address(bridge->scratch_page_page);
 
 		if (bridge->driver->agp_unmap_page)
-			bridge->driver->agp_unmap_page(va,
-					       bridge->scratch_page_dma);
+			bridge->driver->agp_unmap_page(bridge->scratch_page_page,
+						       bridge->scratch_page_dma);
 
 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);